Optical device

ABSTRACT

An example of an optical device of the present disclosure includes a substrate, an obverse-surface conductive layer, a reverse-surface conductive layer, a first conductive part, an optical element and a reflector. The first conductive part extends through the substrate and overlaps with a first obverse-surface conducting region of the overse-surface conductive layer and the reverse-surface conductive layer as viewed in a thickness direction of the substrate. The reflector has an inner surface that surrounds the optical element as viewed in the thickness direction. The optical element is located on first obverse-surface conducting region, and the second obverse-surface conducting region is located between the first obverse-surface conducting region and the inner surface of the reflector as viewed in the thickness direction. A second obverse-surface conducting region of the overse-surface conductive layer is spaced apart from the inner surface of the reflector as viewed in the thickness direction.

FIELD

The present disclosure relates to optical devices.

BACKGROUND

In one example, a conventional semiconductor light-emitting deviceincludes a substrate, a light-emitting element, a wiring pattern, abonding layer and a sealing resin. The wiring pattern is formed on thesubstrate. The semiconductor light-emitting element is disposed on thewiring pattern via the bonding layer. The sealing resin is disposed onthe substrate to cover the semiconductor light-emitting element and thewiring pattern.

SUMMARY

A first aspect of the present disclosure provides an optical device. Theoptical device includes a substrate, an obverse-surface conductivelayer, a reverse-surface conductive layer, a first conductive part, anoptical element and a reflector. The substrate has an obverse surfaceand a reverse surface facing away from each other. The obverse-surfaceconductive layer is formed on the obverse surface of the substrate andincludes a first obverse-surface conducting region and a secondobverse-surface conductive region. The reverse-surface conductive layeris formed on the reverse surface of the substrate. The first conductivepart extends through the substrate and overlaps with the firstobverse-surface conducting region and the reverse-surface conductivelayer as viewed in a thickness direction of the substrate. The opticalelement is disposed on the obverse-surface conductive layer. Thereflector is disposed on the substrate and has an inner surface thatsurrounds the optical element as viewed in the thickness direction. Theoptical element is located on first obverse-surface conducting region,and the second obverse-surface conducting region is located between thefirst obverse-surface conducting region and the inner surface of thereflector as viewed in the thickness direction. The secondobverse-surface conducting region is spaced apart from the inner surfaceof the reflector as viewed in the thickness direction.

DRAWINGS

FIG. 1 is a perspective view of an optical device according to a firstembodiment;

FIG. 2 is a front view of the optical device according to the firstembodiment;

FIG. 3 is a rear view of the optical device according to the firstembodiment;

FIG. 4 is a left-side view of the optical device according to the firstembodiment;

FIG. 5 is a right-side view of the optical device according to the firstembodiment;

FIG. 6 is a plan view of the optical device according to the firstembodiment;

FIG. 7 is a sectional view taken along line VII-VII of FIG. 6;

FIG. 8 is a sectional view taken along line VIII-VIII of FIG. 6;

FIG. 9 is a bottom view of the optical device according to the firstembodiment;

FIG. 10 is an enlarged view showing a part around the optical element ofthe first embodiment;

FIG. 11 is a plan view of an optical device according to a variation ofthe first embodiment;

FIG. 12 is a view showing a step of manufacturing the optical elementaccording to the first embodiment;

FIG. 13 is a view showing a step of manufacturing the optical elementaccording to the first embodiment;

FIG. 14 is a view showing a step of manufacturing the optical elementaccording to the first embodiment;

FIG. 15 is a plan view of an optical device according to a firstvariation of the first embodiment;

FIG. 16 is a sectional view taken along line XVI-XVI of FIG. 15;

FIG. 17 is a sectional view taken along line XVII-XVII of FIG. 15;

FIG. 18 is a view showing a step of manufacturing the optical elementaccording to the first variation of the first embodiment;

FIG. 19 is a plan view of an optical device according to a secondvariation of the first embodiment;

FIG. 20 is a sectional view taken along line XX-XX of FIG. 19;

FIG. 21 is a bottom view of the optical device according to the secondvariation of the first embodiment;

FIG. 22 is a perspective view of a semiconductor device (with a sealingresin shown in shown in phantom) according to a second embodiment of thepresent disclosure;

FIG. 23 is a plan view of the semiconductor device (with the sealingresin shown in phantom) of FIG. 22;

FIG. 24 shows the semiconductor device of FIG. 23, without coatings andthe sealing resin;

FIG. 25 is a bottom view of the semiconductor device of FIG. 22;

FIG. 26 is a left-side view of the semiconductor device of FIG. 22;

FIG. 27 is a sectional view taken along line VI-VI of FIG. 23;

FIG. 28 is a partially enlarged view of FIG. 27 (showing a part around aconcavity);

FIG. 29 is a partially enlarged view of FIG. 27 (showing a part around asemiconductor element);

FIG. 30 is a plan view illustrating a method of manufacturing thesemiconductor device of FIG. 22;

FIG. 31 is a sectional view taken along line XXXI-XXXI of FIG. 30;

FIG. 32 is a sectional view illustrating the method of manufacturing thesemiconductor device of FIG. 22;

FIG. 33 is a plan view illustrating the method of manufacturing thesemiconductor device of FIG. 22;

FIG. 34 is a plan view illustrating the method of manufacturing thesemiconductor device of FIG. 22;

FIG. 35 is a sectional view taken along line XXXV-XXXV of FIG. 34;

FIG. 36 is a plan view illustrating the method of manufacturing thesemiconductor device of FIG. 22;

FIG. 37 is a sectional view taken along line XXXVII-XXXVII of FIG. 36;

FIG. 38 is a plan view illustrating the method of manufacturing thesemiconductor device of FIG. 22;

FIG. 39 is a plan view illustrating the method of manufacturing thesemiconductor device of FIG. 22;

FIG. 40 is a sectional view of the semiconductor device shown in FIG.22, disposed on a wired substrate;

FIG. 41 is a plan view of a semiconductor device (with a sealing resinshown in phantom) according to a third embodiment of the presentdisclosure;

FIG. 42 is a plan view of the semiconductor device shown in FIG. 41,with the coatings and the sealing resin omitted;

FIG. 43 is a left-side view of the semiconductor device of FIG. 41;

FIG. 44 is a sectional view taken along line XLIV-XLIV of FIG. 41; and

FIG. 45 is a partially enlarged view of FIG. 44 (showing a part aroundthe semiconductor element).

EMBODIMENTS

The following describes embodiments of the present disclosure, withreference to the drawings.

In the present disclosure, unless specifically noted otherwise, thestatements that read “object A is formed on object B” and “object A isformed over object B” encompass that “object A is formed directly onobject B” as well as “object A is formed with another object betweenobject A and object B”. Similarly, unless specifically noted otherwise,the statements that read “object A is disposed on object B” and “objectA is disposed over object B” encompass that “object A is disposeddirectly on object B” as well as “object A is disposed with anotherobject between object A and object B”. Similarly, unless specificallynoted otherwise, the statements that read “object A is laminated onobject B” and “object A is laminated over object B” encompass that“object A is laminated directly on object B” as well as “object A islaminated with another object between object A and object B”.

First Embodiment

With reference to FIGS. 1 to 14, a first embodiment of the presentdisclosure is described.

FIG. 1 is a perspective view of an optical device according to the firstembodiment. FIG. 2 is a front view of the optical device according tothe first embodiment. FIG. 3 is a rear view of the optical deviceaccording to the first embodiment. FIG. 4 is a left-side view of theoptical device according to the first embodiment. FIG. 5 is a right-sideview of the optical device according to the first embodiment. FIG. 6 isa plan view of the optical device according to the first embodiment.

The optical device A1 shown in the figures includes a substrate 1, anobverse-surface conductive layer 31, a first conductive part 34A, asecond conductive part 34B, a reverse-surface conductive layer 38, anoptical element 41, a wire 42, a bonding layer 5 and a reflector 8.

The substrate 1 may be made of insulating material, such as insulatingresin or ceramics. Examples of insulating resins include an epoxy resin(which may contain glass or paper), a phenolic resin, polyimide andpolyester. Examples of ceramics include Al₂O₃, SiC and AlN. Thesubstrate 1 may be made of metal, such as aluminum, coated with aninsulating film. The substrate 1 is rectangular as viewed from athickness direction Z1 of the substrate 1.

The substrate 1 has an obverse surface 11, a reverse surface 13, a firstside surface 15A, a second side surface 15B, a third side surface 15Cand a fourth side surface 15D. The obverse surface 11, the reversesurface 13, the first side surface 15A, the second side surface 15B, thethird side surface 15C and the fourth side surface 15D are allrectangular.

The obverse surface 11 and the reverse surface 13 are spaced apart inthe thickness direction Z1 of the substrate 1 and face away from eachother. The obverse surface 11 and the reverse surface 13 are both flat.

The first side surface 15A and the second side surface 15B are spacedapart in a first direction X1 and face away from each other. The firstside surface 15A and the second side surface 15B are both connected tothe obverse surface 11 and the reverse surface 13. The first sidesurface 15A and the second side surface 15B are both flat.

The third side surface 15C and the fourth side surface 15D are spacedapart in a second direction Y1 that is perpendicular to the firstdirection X1 and to the thickness direction Z1 and face away from eachother. The third side surface 15C and the fourth side surface 15D areconnected to both the obverse surface 11 and the reverse surface 13. Thethird side surface 15C and the fourth side surface 15D are both flat.

The obverse-surface conductive layer 31, the first conductive part 34A,the second conductive part 34B and the reverse-surface conductive layer38 shown, for example, in FIG. 6 form an electric current path throughwhich electric power is supplied to the optical element 41. Theobverse-surface conductive layer 31, the first conductive part 34A, thesecond conductive part 34B and the reverse-surface conductive layer 38are made of one or more metals, such as Cu, Ni, Ti and Au. In thepresent embodiment, as shown in FIG. 7, the obverse-surface conductivelayer 31, as well as the reverse-surface conductive layer 38, is made ofCu (a layer 391 may be a Cu layer) plated with Au (a layer 392 may be aAu layer). The materials of the obverse-surface conductive layer 31, thefirst conductive part 34A, the second conductive part 34B and thereverse-surface conductive layer 38 are not limited to those mentionedabove.

The obverse-surface conductive layer 31 is formed on the obverse surface11 of the substrate 1 and includes a first obverse-surface conductiveregion 311A, a second obverse-surface conductive region 312A, a thirdobverse-surface conductive region 313A and a fourth obverse-surfaceconductive region 31B.

The optical element 41 is disposed on the first obverse-surfaceconductive region 311A. In the present embodiment, the firstobverse-surface conductive region 311A has an outer perimeter that isgenerally circular. The term “circular” used herein encompasses shapesthat are perfectly circular and roughly circular, and the same applieshereinafter. In a different embodiment, the first obverse-surfaceconductive region 311A may have a different shape (e.g., rectangular)than a circular shape. Note that the term “rectangular” used hereinencompasses shapes that are perfectly rectangular and roughlyrectangular, and the same applies hereinafter.

The second obverse-surface conductive region 312A is spaced apart fromthe first obverse-surface conductive region 311A in the first directionX1. In a different embodiment, the second obverse-surface conductiveregion 312A may be spaced apart in an oblique direction to the firstdirection X1. In the present embodiment, the second obverse-surfaceconductive region 312A has an outer perimeter that is generallyelliptical. The term “elliptical” used herein encompasses shapes thatare perfectly elliptical shape, as well as shapes that are roughlyelliptical, and the same applies hereinafter. In a different embodiment,the second obverse-surface conductive region 312A may have a differentshape (e.g., rectangular or circular) than an elliptical shape.

The third obverse-surface conductive region 313A is located between thefirst obverse-surface conductive region 311A and the secondobverse-surface conductive region 312A as viewed in the thicknessdirection Z1, connecting the first obverse-surface conductive region311A and the second obverse-surface conductive region 312A. The thirdobverse-surface conductive region 313A extends from the firstobverse-surface conductive region 311A in the first direction X1. Asshown in FIG. 6, the third obverse-surface conductive region 313A has adimension L13 in the second direction Y1, and this dimension L13 may besmaller than the dimension L11 of the first obverse-surface conductiveregion 311A in the second direction Y1. In addition, the dimension L13of the third obverse-surface conductive region 313A may be smaller thanthe dimension L12 of the second obverse-surface conductive region 312Ain the second direction Y1.

To the fourth obverse-surface conductive region 31B, the wire 42 isbonded. The fourth obverse-surface conductive region 31B is spaced apartfrom the first obverse-surface conductive region 311A in the firstdirection X1. In the present embodiment, the fourth obverse-surfaceconductive region 341A has an outer perimeter that is generallyelliptical. In a different embodiment, the fourth obverse-surfaceconductive region 31B may have a different shape (e.g., rectangular orcircular) than an elliptical shape.

FIG. 7 is a sectional view taken along line VII-VII of FIG. 6. FIG. 8 isa sectional view taken along line VIII-VIII of FIG. 6. FIG. 9 is abottom view of the optical device according to the first embodiment.

As shown in FIGS. 7 to 9, the reverse-surface conductive layer 38 isformed on the reverse surface 13 of the substrate 1. The reverse-surfaceconductive layer 38 includes a first reverse-surface conductive region38A and a second reverse-surface conductive region 38B.

The first reverse-surface conductive region 38A has apart overlappingwith the second obverse-surface conductive region 312A as viewed in thethickness direction Z1 of the substrate 1. As viewed in the thicknessdirection Z1, the first reverse-surface conductive region 38A extendsacross the reverse surface 13 of the substrate 1 from the boundary withthe third side surface 15C to the boundary with the fourth side surface15D. This configuration of the present embodiment aims to enable platingto be carried out in the manufacture of multiple optical devices A1, byallowing an electric current to flow through wiring patterns of theoptical devices A1 (to form the reverse-surface conductive layers 38 andother layers). In the present embodiment, the first reverse-surfaceconductive region 38A is composed of segments 381AA, 382AA and 383AA.The segment 381AA is rectangular. The segment 382AA extends from thesegment 381AA to the boundary between the reverse surface 13 and thethird side surface 15C of the substrate 1. The segment 382AA is at aposition offset from the first conductive part 34A in the direction X1.The segments 383AA extends from the segment 381AA to the boundarybetween the reverse surface 13 and the fourth side surface 15D of thesubstrate 1. The segment 383AA is at a position offset from the firstconductive part 34A in the first direction X1. The segments 382AA and383AA located offset from the first conductive part 34A in the directionX1 are preferable because this configuration allows solder to be appliedin more preferable shapes to mount the optical device A1. This providesthe optical device A1 that can be mounted more easily.

The second reverse-surface conductive region 38B is spaced apart fromthe first reverse-surface conductive region 38A in the first directionX1. The second reverse-surface conductive region 38B has a partoverlapping with the fourth obverse-surface conductive region 31B asviewed in the thickness direction Z1 of the substrate 1. As viewed inthe thickness direction Z1, the second reverse-surface conductive region38B extends across the reverse surface 13 of the substrate 1 from theboundary with the third side surface 15C to the boundary with the fourthside surface 15D. This configuration of the present embodiment aims toenable plating to be carried out in the manufacture of multiple opticaldevices A1, by allowing an electric current to flow through the wiringpatterns of the optical devices A1 (to form the reverse-surfaceconductive layer 38 and other layers). In the present embodiment, thesecond reverse-surface conductive region 38B is composed of segments381BB, 382BB and 383BB. The segment 381BB is rectangular. The segment382BB extends from the segment 381BB to the boundary between the reversesurface 13 and the third side surface 15C of the substrate 1. Thesegment 382BB is at a position offset from the second conductive part34B in the first direction X1. The segment 383BB extends from thesegment 381BB to the boundary between the reverse surface 13 and thefourth side surface 15D of the substrate 1. The segment 383BB is at aposition offset from the second conductive part 34B in the firstdirection X1. The segments 382BB and 383BB located offset from thesecond conductive part 34B in the direction X1 are preferable becausethis configuration allows solder to be applied to in more preferableshapes to mount the optical device A1. This provides the optical deviceA1 that can be mounted more easily.

The first conductive part 34A shown, for example, in FIGS. 6 and 7extends through the substrate 1. More specifically, the first conductivepart 34A is formed in a through hole formed in the substrate 1. Thefirst conductive part 34A overlaps with the first obverse-surfaceconductive region 311A and the first reverse-surface conductive region38A as viewed in the thickness direction Z1 of the substrate 1. Thefirst conductive part 34A connects the first obverse-surface conductiveregion 311A to the first reverse-surface conductive region 38A. Asviewed in the thickness direction Z1, the entire region of the firstconductive part 34A overlaps with the first obverse-surface conductiveregion 311A and also with the first reverse-surface conductive region38A. In an example shown in FIG. 11 different from FIG. 6, the firstconductive part 34A may overlap with the second obverse-surfaceconductive region 312A as viewed in the thickness direction Z1.

The second conductive part 34B extends through the substrate 1. Morespecifically, the second conductive part 34B is formed in a through holeformed in the substrate 1. As viewed in the thickness direction of thesubstrate 1, the second conductive part 34B overlaps with the fourthobverse-surface conductive region 31B and also with the secondreverse-surface conductive region 38B. The second conductive part 34Bconnects the fourth obverse-surface conductive region 31B to the secondreverse-surface conductive region 38B. As viewed in the thicknessdirection Z1, the entire region of the second conductive part 34Boverlaps with the fourth obverse-surface conductive region 31B and alsowith the second reverse-surface conductive region 38B.

In the present embodiment, the first conductive part 34A and the secondconductive part 34B are circular as viewed in the thickness directionZ1. In a different embodiment, the first conductive part 34A and thesecond conductive part 34B may have a non-circular shape as viewed inthe thickness direction Z1.

The optical element 41 shown, for example, in FIG. 7 is disposed on thefirst obverse-surface conductive region 311A. In general, opticalelements include light-emitting elements and light-receiving elements.In the present embodiment, the optical element 41 is a light-emittingelement used as a light source of the optical device A1. Morespecifically, the optical element 41 in the present embodiment is an LEDchip having an n-type semiconductor layer, an active layer and a p-typesemiconductor layer. The n-type semiconductor layer is laminated on theactive layer, which is laminated on the p-type semiconductor layer. Thatis, the active layer is located between the n-type semiconductor layerand the p-type semiconductor layer. The n-type semiconductor layer, theactive layer and the p-type semiconductor layer may be made of GaN, forexample. The optical element 41 includes an obverse-surface electrodepad and a reverse-surface electrode pad facing away from each other.Note that the obverse- and reverse-surface electrode pads are not shownin the figures. The optical element 41 is mounted on the substrate 1.The emission color of the optical element 41 is not specificallylimited.

The wire 42 is bonded to the optical element 41 and the fourthobverse-surface conductive region 31B. The wire 42 is made of aconductive material and electrically connects the optical element 41 tothe fourth obverse-surface conductive region 31B. In the presentembodiment, the wire 42 extends in the first direction X1 as viewed inthe thickness direction Z1.

As shown, for example, in FIGS. 7 and 10, the bonding layer 5 is locatedbetween the optical element 41 and the first obverse-surface conductiveregion 311A. The bonding layer 5 may be made from a silver paste. In adifferent embodiment, however, the bonding layer 5 may be made from aninsulating material. In the present embodiment, the bonding layer 5 ispreferably in contact with the side surfaces 411 of the optical element41 and the first obverse-surface conductive region 311A, so that theoptical element 41 can be held more firmly.

The reflector 8 shown, for example, in FIGS. 6, 7 and 8 is disposed onthe substrate 1. The reflector 8 may be bonded to the substrate 1 via abonding layer 89. As shown in FIGS. 7 and 8, the bonding layer 89 mayhave a segment 891 projecting inward beyond the reflector 8. Note thatother embodiments and variations, which will be described layer, mayalso have a bonding layer 89 provided with a segment 891 shown in FIGS.7 and 8. Preferably, the reflector 8 is made of a material that blockstransmission of light. In particular, where the optical element 41 is alight-emitting element, the reflector 8 may be made of a material notallowing passage of light emitted from the light-emitting element. In acase where the optical element 41 is a light-receiving element, thereflector 8 may be made of a material not allowing passage of light thatcan be received by the light-receiving element. The reflector 8 may beformed integrally (i.e., an integral piece). In a case where the opticalelement 41 is a light-emitting element, the reflector 8 can restrictlateral leakage of light emitted from the optical element 41.

In the present embodiment, the reflector 8 and the substrate 1 containthe same material. In one example, the reflector 8 is made of an epoxyresin, whereas the substrate 1 is made of an epoxy resin containingglass. That is to say, the reflector 8 and the substrate 1 both containan epoxy resin. In a different embodiment, the reflector 8 and thesubstrate 1 may be made of mutually different materials. For example,the reflector 8 may be made of a liquid crystal polymer or nylon.

The reflector 8 has a reflector-obverse surface 811, a reflector-reversesurface 812, a first reflector-outer surface 81A, a secondreflector-outer surface 81B, a third reflector-outer surface 81C, afourth reflector-outer surface 81D and an inner surface 83.

The reflector-obverse surface 811 faces in the same direction as theobverse surface 11 of the substrate 1. In the present embodiment, thereflector-obverse surface 811 has an edge 811A and an edge 811B. Theedge 811A of the reflector-obverse surface 811 is an outer edge defininga rectangular shape. The edge 811B of the reflector-obverse surface 811is an inner edge defining a curved shape. In the embodiment shown, forexample, in FIG. 3, the separation distance of the edge 811B from theobverse surface 11 of the substrate 1 in the Z1 direction is smallerthan that of the edge 811A. This configuration is preferable, in themanufacture of the optical device A1, for manipulating tools to hold theoptical element 41 or to bond a wire without the tools touching theinner surface 83 of the reflector 8. This configuration is alsopreferable, in the transport of the optical device A1, for a grippingtool to grip the optical device A1 by, for example, the reflector-outersurfaces 81C and 81D. The reflector-obverse surface 811 includes a flatregion and a curved region. The reflector-reverse surface 812 faces awayfrom the reflector-obverse surface 811. In this embodiment, thereflector-reverse surface 812 is flat.

The inner surface 83 is connected to the reflector-obverse surface 811and the reflector-reverse surface 812. The inner surface 83 extends fromthe reflector-obverse surface 811 to the reflector-reverse surface 812.In the present embodiment, the inner surface 83 forms an angle of 90°with the reflector-obverse surface 811 and also with thereflector-reverse surface 812. In a different embodiment, the innersurface 83 may form an angle other than 90° with each of thereflector-obverse surface 811 and the reflector-reverse surface 812. Inshort, the inner surface 83 may be inclined with respect to thedirection Z1.

As shown in FIG. 6, the inner surface 83 surrounds the optical element41 as viewed in the thickness direction Z1. In the present embodiment,the entire regions of the obverse-surface conductive layer 31 arelocated entirely inside the inner surface 83 as viewed in the thicknessdirection Z1. Similarly, the entire regions of the first conductive part34A and the second conductive part 34B are located inside the innersurface 83 as viewed in the thickness direction Z1. In FIG. 6, thesecond obverse-surface conductive region 312A is located between thefirst obverse-surface conductive region 311A and the inner surface 83 ofthe reflector 8 as viewed in the thickness direction Z1. The secondobverse-surface conductive region 312A is separated from the innersurface 83 at a separation distance LA, which may be 40 to 100 μm, forexample. The separation distance LA may be smaller than the separationdistance LB between the second obverse-surface conductive region 312Aand the first obverse-surface conductive region 311A. In FIG. 6, thefourth obverse-surface conductive region 31B is separated from the innersurface 83 of the reflector 8 as viewed in the thickness direction Z1.The separation distance LC of the fourth obverse-surface conductiveregion 31B from the inner surface 83 may be 40 to 100 μm, for example.

The inner surface 83 includes a first segment 83A, a second segment 83B,a third segment 83C and a fourth segment 83D. The first segment 83A andthe second segment 83B are spaced apart from each other in the firstdirection X1. In the present embodiment, each of the first segment 83Aand the second segment 83B is semicircular as viewed in the thicknessdirection Z1. The third segment 83C and the fourth segment 83D arespaced apart from each other in the second direction Y1. The thirdsegment 83C and the fourth segment 83D are each connected to the firstsegment 83A and the second segment 83B. In the present embodiment, eachof the third segment 83C and the fourth segment 83D is substantiallystraight as viewed in the thickness direction Z1.

In a different embodiment, the first segment 83A and the second segment83B may be substantially straight instead of semicircular. In anotherdifferent embodiment, the inner surface 83 may have a circular shape asviewed in the thickness direction Z1.

As shown, for example, in FIGS. 6 and 7, the reflector-outer surface 81Aand the second reflector-outer surface 81B are spaced apart in the firstdirection X1 and face away from each other. The first reflector-outersurface 81A and the second reflector-outer surface 81B are bothconnected to the reflector-obverse surface 811 and the reflector-reversesurface 812. The first reflector-outer surface 81A and the secondreflector-outer surface 81B are both flat.

As shown, for example, in FIGS. 6 and 8, the third reflector-outersurface 81C and the fourth reflector-outer surface 81D are spaced apartin the second direction Y1 and face away from each other. The thirdreflector-outer surface 81C and the fourth reflector-outer surface 81Dare both connected to the reflector-obverse surface 811 and thereflector-reverse surface 812. The third reflector-outer surface 81C andthe fourth reflector-outer surface 81D are both flat.

The first side surface 15A is flush with the first reflector-outersurface 81A. Similarly, the second side surface 15B is flush with thesecond reflector-outer surface 81B, the third side surface 15C with thethird reflector-outer surface 81C, and the fourth side surface 15D withthe fourth reflector-outer surface 81D. This is because the substrate 1and the reflector 8 are cut at a time in a dicing process, respectivelyfrom a substrate 100 and a reflector 800 (both of which will bedescribed later).

The following now describes a method for manufacturing the opticaldevice A1 according to the present embodiment, with reference to FIGS.12 to 14. In particular, the present embodiment provides an example inwhich a plurality of optical devices A1 are manufactured. In thefollowing description, the same reference signs as above are used todenote the same or similar elements.

First, a rectangular substrate 100 (see FIG. 12) is prepared. As shown,for example, in FIG. 12, the substrate 100 is of a size large enough formultiple substrates 1. The substrate 100 is made of the same material(glass epoxy resin) as described above for the substrate 1. Next, wiringpatterns (corresponding to the obverse-surface conductive layers 31, thereverse-surface conductive layers 38 and so on) are formed on thesubstrate 100. The wiring patterns are formed by plating Cu foil withAu.

Next, as shown in FIG. 13, a reflector 800 is attached to the substrate100 using an adhesive, for example. The reflector 800 has a plurality ofopenings (each having an inner surface 83) formed by, for example,drilling or molding.

Next, as shown in FIG. 14, optical elements 41 are disposed on theobverse-surface conductive layers 31 via bonding layers 5. Then, wires42 are attached by wire bonding to connect the optical elements 41 tothe obverse-surface conductive layer 31. As a result, each opticalelement 41 is electrically connected to an obverse-surface conductivelayer 31.

Next, the thus obtained intermediate product shown in FIG. 14 is dicedalong lines 899 into a plurality of optical devices A1, each of which isidentical to the one shown, for example, in FIG. 6. In the process ofdicing the intermediate product, the substrate 100 and the reflector 800are cut at a time. Although the manufacturing method is described usingan example in which a plurality of optical devices A1 are manufacturedat a time, the optical devices A1 may as well be manufactured one by oneat a time.

Now, advantages of the present embodiment are described.

In the present embodiment, the first obverse-surface conductive region311A is where the optical element 41 is mounted, and the secondobverse-surface conductive region 312A is located between the firstobverse-surface conductive region 311A and the inner surface 83 of thereflector 8 as viewed in the thickness direction Z1. The secondobverse-surface conductive region 312A is spaced apart from the innersurface 83 of the reflector 8 as viewed in the thickness direction Z1.This configuration allows the reflector 8 to be located where the secondobverse-surface conductive region 312A is not present, so that thereflector 8 a can be securely mounted on the substrate 1. In addition,the reflector 8 can reflect light from the optical element 41 at higherbrightness.

The present embodiment ensures that the reflector 8 (i.e., reflector 800in FIG. 13) is placed on the substrate 1 without covering the secondobverse-surface conductive region 312A as much as possible. Thisconfiguration ensures as much as possible that the reflector 8 is notdisposed on an uneven surface due to a step formed by the secondobverse-surface conductive region 312A. As a result, the reflector 8 canbe securely mounted on the substrate 1 without being inclined.

In the present embodiment, all the regions of the obverse-surfaceconductive layer 31 are located inside the inner surface 83 as viewed inthe thickness direction Z1. This configuration ensures that thereflector 8 does not overlap with the obverse-surface conductive layer31, enabling the reflector 8 to be securely mounted on the substratewithout being inclined.

In the present embodiment, the optical device A1 includes the bondinglayer 5 located between and in contact with the optical element 41 andthe obverse-surface conductive layer 31. The present embodiment ensuresthe following during the manufacture of the optical device A1. That is,when a paste for forming the bonding layer 5 is applied to the firstobverse-surface conductive region 311A, the paste is not allowed to flowinto the second obverse-surface conductive region 312A and then to reachthe inner surface 83 of the reflector 8. That is, the paste is kept fromflowing across the inner surface 83 of the reflector 8 to reach anotherregion of the obverse-surface conductive layer 31 (the fourthobverse-surface conductive region 31B, for example). This provides anadvantage of minimizing the risk of a short circuit between the fourthobverse-surface conductive region 31B and the second obverse-surfaceconductive region 312A, even if the bonding layer 5 has electricalconductivity.

In the present embodiment, the reflector 8 and the substrate 1 containthe same material, ensuring that the reflector 8 and the substrate 1have the same or similar thermal expansion coefficient. Consequently,the reflector 8 and the substrate 1 are expected to undergo the samedegree of thermal expansion or contraction, which is effective inkeeping the reflector 8 and the substrate 1 from warping.

First Variation of First Embodiment

With reference to FIGS. 15 to 18, a first variation of the firstembodiment of the present disclosure is described.

In the following description, the same reference signs as above are usedto denote the same or similar elements.

FIG. 15 is a plan view of an optical device according to the firstvariation of the first embodiment. FIG. 16 is a sectional view takenalong line XVI-XVI of FIG. 15. FIG. 17 is a sectional view taken alongline XVII-XVII of FIG. 15.

The optical device A2 of the present variation is similar to the opticaldevice A1, except that a light-transmitting resin package 7 isadditionally included. In FIGS. 15 to 17, the light-transmitting resinpackage 7 is shown by dash-double-dot lines.

The light-transmitting resin package 7 is disposed on the substrate 1.Specifically, the light-transmitting resin package 7 covers thesubstrate 1, the optical element 41, the obverse-surface conductivelayer 31, the wire 42 and the reflector 8. The light-transmitting resinpackage 7 is made of a material that passes light. In particular, in acase where the optical element 41 is a light-emitting element, thelight-transmitting resin package 7 may be made of a material allowingpassage of light emitted from the light-emitting element. In a casewhere the optical element 41 is a light-receiving element, thelight-transmitting resin package 7 may be made of a material allowingpassage of light that can be received by the light-receiving element.Examples of resins usable to form the light-transmitting resin package 7include a transparent or semi-transparent epoxy resin, silicone resin,acrylic resin and polyvinyl resin.

The light-transmitting resin package 7 may be formed integrally (i.e.,an integral piece). The light-transmitting resin package 7 may contain afluorescent material that emits light of a different wavelength whenexcited by the light from the optical element. In this variation, thelight-transmitting resin package 7 contains no filler, unlike a resinpackage of so-called a black resin. The light-transmitting resin package7 may be formed by molding.

The light-transmitting resin package 7 has a first light-transmittingsegment 71 and a second light-transmitting segment 72. The firstlight-transmitting segment 71 is located between the secondlight-transmitting segment 72 and the substrate 1. The firstlight-transmitting segment 71 has light-transmitting outer surfaces711A, 711B, 711C and 711D.

The light-transmitting outer surface 711A is flush with thereflector-obverse surface 811 of the reflector 8. Similarly, thelight-transmitting outer surface 711B is flush with thereflector-obverse surface 811 of the reflector 8. In the manufacture ofthe optical device A2, the light-transmitting outer surfaces 711A and711B and the reflector-obverse surface 811 are formed by pressing flatsurfaces of a mold thereagainst. The light-transmitting outer surfaces711C and 711D (two light-transmitting outer surfaces) face away fromeach other. The light-transmitting outer surface 711C is flat and flushwith the third reflector-outer surface 81C and with the third sidesurface 15C. Similarly, the light-transmitting outer surface 711D isflat and flush with the fourth reflector-outer surface 81D and with thefourth side surface 15D. This is because the substrate 1, the reflector8, and the light-transmitting resin package 7 are cut at a time in adicing process, respectively from a substrate 100, a reflector 800 and alight-transmitting resin package 700 (all of which will be describedlater).

The second light-transmitting segment 72 has a curved surface 721, whichis curved outward in the direction from the substrate 1 to the opticalelement 41. The curved surface 721 overlaps with the optical element 41as viewed in the thickness direction Z1.

The optical device A2 is manufactured through the same steps as with theoptical device A1 up to the steps shown in FIG. 14. In a step subsequentto the step shown in FIG. 14, a light-transmitting resin package 700 isformed on the substrate 100 by die molding to obtain an intermediateproduct shown in FIG. 18. Next, the intermediate product is diced alonglines 892 into a plurality of optical devices A2.

This variation provides the following advantages in addition to thoseprovided by the optical device A1.

In the optical device A2 as shown in FIG. 17, the light-transmittingouter surface 711C is flush with the third reflector-outer surface 81Cand the light-transmitting outer surface 711D is flush with the fourthreflector-outer surface 81D. In a case where the optical element 41 is alight-emitting element, this configuration ensures total reflection tooccur at the light-transmitting outer surface 711C and thelight-transmitting outer surface 711D. As a result, more light emittedfrom the light-emitting element and traveling in the light-transmittingresin package 7 can exit in the thickness direction Z1. In a case wherethe optical element 41 is a light-receiving element, this configurationallows more light traveling toward the optical device A2 in thethickness direction Z1 to be received by the light-receiving element. Inthis way, the optical device A2 of improved capability is provided.

Second Variation of First Embodiment

With reference to FIGS. 19 to 21, the following describes a secondvariation of the embodiment of the present disclosure.

FIG. 19 is a plan view of an optical device according to the secondvariation of the first embodiment. FIG. 20 is a sectional view takenalong line XX-XX of FIG. 19. FIG. 21 is a plan view of the opticaldevice according to the second variation of the first embodiment.

An optical device A3 of this variation is similar to the optical deviceA2, other than the shapes of the obverse-surface conductive layer, thereverse-surface conductive layer, the first conductive part and thesecond conductive part.

The substrate 1 has an obverse surface 11, a reverse surface 13, a firstside surface 15A, a second side surface 15B, a third side surface 15Cand a fourth side surface 15D.

The obverse surface 11 and the reverse surface 13 are spaced apart inthe thickness direction Z1 of the substrate 1 and face away from eachother. The obverse surface 11 and the reverse surface 13 are both flat.

The first side surface 15A and the second side surface 15B are spacedapart in the first direction X1 and face away from each other. The firstside surface 15A and the second side surface 15B are both connected tothe obverse surface 11 and the reverse surface 13. The first sidesurface 15A and the second side surface 15B are both flat.

The substrate 1 has a first concavity 16A and a second concavity 16Bthat are recessed inward from the first side surface 15A and the secondside surface 15B, respectively. The first concavity 16A and the secondconcavity 16B both extend from the obverse surface 11 to the reversesurface 13. In the present embodiment, each of the first concavity 16Aand the second concavity 16B is semicircular as viewed in the thicknessdirection Z1 of the substrate 1.

The third side surface 15C and the fourth side surface 15D are spacedapart in the second direction Y1 and face away from each other. Thethird side surface 15C and the fourth side surface 15D are bothconnected to the obverse surface 11 and the reverse surface 13. Thethird side surface 15C and the fourth side surface 15D are both flat.

The obverse-surface conductive layer 31 includes a first obverse-surfaceconductive region 311A, a second obverse-surface conductive region 312A,a first end region 35A, a fourth obverse-surface conductive region 31Band a second end region 35B. The description of the firstobverse-surface conductive region 311A is omitted here because therelevant description given for the optical device A1 applies here.

The second obverse-surface conductive region 312A extends from the firstobverse-surface conductive region 311A in the first direction X1. Asshown in FIG. 19, the first end region 35A extends along an edge 161A ofthe first concavity 16A. In the present embodiment, the first end region35A has a half-annular shape. The first end region 35A is continuouswith the fourth obverse-surface conductive region 31B. The second endregion 35B extends along the edge 161B of the second concavity 16B. Inthe present embodiment, the second end region 35B has a half-annularshape. The second end region 35B is continuous with the secondobverse-surface conductive region 312A.

The first conductive part 37A is formed on the inner surface of thefirst concavity 16A and connected to the first end region 35A. Thesecond conductive part 37B is formed on the inner surface of the secondconcavity 16B and connected to the second end region 35B. When theoptical device A3 is mounted on a wired substrate, solder adheres to thefirst conductive part 37A and the second conductive part 37B and formssolder fillets.

As shown in FIG. 21, the reverse-surface conductive layer 38 includes afirst reverse-surface conductive region 38A and a second reverse-surfaceconductive region 38B.

The first reverse-surface conductive region 38A is connected to thefirst conductive part 37A. The first reverse-surface conductive region38A has edges 381A to 387A. The edge 381A extends in the first directionX1. The edge 382A extends in the second direction Y1 from the edge 381A.The edge 383A extends in the first direction X1 from the edge 382A. Theedge 384A extends in the second direction Y1 from the edge 381A. Theedge 384A is shorter than the edge 382A. The edge 385A defines acircular arc extending from the edge 384A. The edge 385A reaches anouter edge of the reverse surface 13 of the substrate 1 in the firstdirection X1. The edge 386A extends in the second direction Y1 from theedge 383A. The edge 386A is shorter than the edge 382A. The edge 387Adefines a circular extending from the edge 386A. The edge 387A reachesthe outer edge of the reverse surface 13 of the substrate 1 in the firstdirection X1.

The second reverse-surface conductive region 38B is connected to thesecond conductive part 37B. The second reverse-surface conductive region38B has edges 381B to 387B. The edge 381B extends in the first directionX1. The edge 382B extends in the second direction Y1 from the edge 381B.The edge 383B extends in the first direction X1 from the edge 382B. Theedge 384B extends in the second direction Y1 from the edge 381B. Theedge 384B is shorter than the edge 382B. The edge 385B defines acircular arc extending from the edge 384B. The edge 385B reaches anouter edge of the reverse surface 13 of the substrate 1 in the firstdirection X1. The edge 386B extends in the second direction Y1 from theedge 383B. The edge 386B is shorter than the edge 382B. The edge 387Bdefines a circular arc extending from the edge 386B. The edge 387Breaches the outer edge of the reverse surface 13 of the substrate 1 inthe first direction X1.

The optical device of this variation provides the same advantages asthose described for the optical device A2.

The present disclosure is not limited to the specific embodimentsdescribed above. Various design modifications may be made to thespecific configurations of each part of the present disclosure.

The first embodiment of the present disclosure encompasses the followingclauses.

Clause A1.

An optical device comprising:

a substrate having an obverse surface and a reverse surface facing awayfrom each other;

an obverse-surface conductive layer formed on the obverse surface of thesubstrate, the obverse-surface conductive layer including a firstobverse-surface conducting region and a second obverse-surfaceconductive region;

a reverse-surface conductive layer formed on the reverse surface of thesubstrate;

a first conductive part extending through the substrate and overlappingwith the first obverse-surface conducting region and the reverse-surfaceconductive layer as viewed in a thickness direction of the substrate;

an optical element disposed on the obverse-surface conductive layer; and

a reflector disposed on the substrate, the reflector having an innersurface that surrounds the optical element as viewed in the thicknessdirection,

wherein the optical element is located on first obverse-surfaceconducting region, and the second obverse-surface conducting region islocated between the first obverse-surface conducting region and theinner surface of the reflector as viewed in the thickness direction, and

wherein the second obverse-surface conducting region is spaced apartfrom the inner surface of the reflector as viewed in the thicknessdirection.

Clause A2.

The optical device according to Clause A1, further comprising a bondinglayer disposed between and in contact with the optical element and theobverse-surface conductive layer.

Clause A3.

The optical device according to Clause A1 or A2,

wherein an entirety of the obverse-surface conductive layer is locatedinside the inner surface as viewed in the thickness direction.

Clause A4.

The optical device according to any of Clauses A1 to A3,

wherein the first conductive part is located inside the inner surface asviewed in the thickness direction.

Clause A5.

The optical device according to any of Clauses A1 to A4,

wherein a distance between the second obverse-surface conducting regionand the inner surface is smaller than a distance between the secondobverse-surface conducting region and the first obverse-surfaceconducting region.

Clause A6.

The optical device according to any of Clauses A1 to A5,

wherein the obverse-surface conductive layer includes a thirdobverse-surface conducting region that is disposed between the firstobverse-surface conducting region and the second obverse-surfaceconducting region as viewed in the thickness direction and that connectsthe first obverse-surface conducting region and the secondobverse-surface conducting region.

Clause A7.

The optical device according to Clause A6,

wherein the third obverse-surface conducting region extends from thefirst obverse-surface conducting region in a first direction, and

wherein the third obverse-surface conducting region is smaller than thefirst obverse-surface conducting region in dimension in a seconddirection that is perpendicular to both the first direction and thethickness direction.

Clause A8.

The optical device according to Clause A7,

wherein the third obverse-surface conducting region is smaller than thesecond obverse-surface conducting region in dimension in the seconddirection.

Clause A9.

The optical device according to any of Clauses A6 to A8, furthercomprising

a wire bonded to the optical element and the obverse-surface conductivelayer,

wherein the obverse-surface conductive layer includes a fourthobverse-surface conducting region to which the wire is bonded, and

wherein the fourth obverse-surface conducting region is spaced apartfrom the inner surface of the reflector as viewed in the thicknessdirection.

Clause A10.

The optical device according to Clause A9, further comprising

a second conductive part that extends through the substrate, the secondconductive part overlapping with the fourth obverse-surface conductingregion and the reverse-surface conductive layer as viewed in thethickness direction of the substrate,

wherein the second conductive part is located inside the inner surfaceas viewed in the thickness direction.

Clause A11.

The optical device according to Clause A10,

wherein the reverse-surface conductive layer includes a firstreverse-surface conductive region and a second reverse-surfaceconductive region,

wherein the first reverse-surface conductive region overlaps with thefirst conductive part and the reflector as viewed in the thicknessdirection, and

wherein the second reverse-surface conductive region overlaps with thesecond conductive part and the reflector as viewed in the thicknessdirection.

Clause A12.

The optical device according to Clause A1,

wherein the substrate has two side surfaces facing away from each other,

wherein the substrate has: a first boundary between the reverse surfaceand one of the side surfaces; and a second boundary between the reversesurface and the other of the side surfaces, and

wherein the reverse-surface conductive layer extends on the reversesurface of the substrate from the first boundary to the second boundaryas viewed in the thickness direction.

Clause A13.

The optical device according to any of Clauses A1 to A12,

wherein the reflector and the substrate contain the same material.

Clause A14.

The optical device according to any of Clauses A11 to A13,

wherein the reflector is made of an opaque material.

Clause A15.

The optical device according to any of Clauses A11 to A14, furthercomprising alight-transmitting resin package disposed on the substrate,

wherein the light-transmitting resin package has two light-transmittingouter surfaces facing away from each other,

wherein the reflector has two reflector outer surfaces facing away fromeach other,

wherein each of the two light-transmitting outer surfaces and the tworeflector outer surfaces is parallel to the thickness direction of thesubstrate, and

wherein the two light-transmitting outer surfaces are flush with the tworeflector outer surfaces, respectively.

Clause A16.

The optical device according to Clause A15,

wherein the light-transmitting resin package has a surface curvedoutward in a direction from the substrate to the optical element.

Second Embodiment

The following describes a semiconductor device A10 according to a secondembodiment of the present disclosure, with reference to FIGS. 22 to 29.The reference numerals in the second and third embodiments are notrelated to the reference numerals in the first embodiment. Thesemiconductor device A10 includes a substrate 1, obverse-surfaceelectrodes 21, reverse-surface electrodes 22, middle electrodes 23,wiring layers 29, a semiconductor element 31, a wire 4, coatings 51 anda sealing resin 52. For convenience, the sealing resin 52 in FIGS. 22and 23 are shown in phantom by the dash-double-dot lines indicating theoutline of the sealing resin 52.

The semiconductor device A10 shown in the figures is an LED packagecontaining a light-emitting diode as the semiconductor element 31. Thesemiconductor device A10 is designed for surface mounting on a wiredsubstrate. As shown in FIGS. 22 and 23, the semiconductor device A10 isrectangular as viewed in the thickness direction z of the substrate 1(hereinafter “plan view”). For convenience of explanation, thelongitudinal direction of the semiconductor device A10 perpendicular tothe thickness direction z of the substrate 1 (hereinafter, simply“thickness direction z”) is referred to as a first direction x. Theshort direction of the semiconductor device A10 perpendicular to boththe thickness direction z and the first direction x is referred to as asecond direction y. In addition, “one direction” used in the presentdisclosure refers to the first direction.

As shown in FIGS. 22 to 27, the substrate 1 is an electrical insulatingmember on which the obverse-surface electrodes 21, the reverse-surfaceelectrodes 22, the middle electrodes 23 and the wiring layers 29 aredisposed and the semiconductor element 31 and the sealing resin 52 aresupported. The substrate 1 may be made of, for example, glass epoxyresin or alumina (Al₂O₃). As shown in FIGS. 22 to 24, the substrate 1 isrectangular elongated in the first direction x in plan view. Thesubstrate 1 has an obverse surface 11, a reverse surface 12 and sidesurfaces 13.

As shown in FIGS. 22 to 24, 26 and 27, the obverse surface 11 faces inone direction along the thickness direction z. The obverse-surfaceelectrodes 21 are disposed on the obverse surface 11, and thesemiconductor element 31 is disposed on one of the obverse-surfaceelectrodes 21. In the present embodiment, the wiring layers 29 and thecoatings 51 are also disposed on the obverse surface 11.

As shown in FIGS. 22 and 25 to 27, the reverse surface 12 faces theother direction along the thickness direction z. That is, the obversesurface 11 and the reverse surface 12 face away from each other in thethickness direction z. The reverse-surface electrodes 22 are disposed onthe reverse surface 12, which are for mounting the semiconductor deviceA10 on a printed substrate.

As shown in FIGS. 22 to 27, each side surfaces 13 meets both the obversesurface 11 and the reverse surface 12. The side surfaces 13 include apair of first side surfaces 131 spaced apart from each other in thefirst direction x and a pair of side surfaces 132 spaced apart from eachother in the second direction y.

As shown in FIGS. 22 to 25, each of the first side surfaces 131 has aconcavity 14 that is recessed inward in the substrate 1 in plan view.Note that neither of the second side surfaces 132 has a concavity 14. Asshown in FIGS. 24 to 28, each concavity 14 is recessed from acorresponding side surface 13 in plan view and has an inner surface 141extending from the obverse surface 11 to the reverse surface 12. Theinner surface 141 includes a pair of first regions 141 a recessed fromthe side surface 13 and a second region 141 b recessed from the firstregions 141 a. In the present embodiment, the first regions 141 a areseparated from each other in the second direction y, and the secondregion 141 b is located therebetween. That is, each concavity 14 of thepresent embodiment is composed of a pair of first regions 141 a and asecond region 141 b forming a two-stepped groove across the substrate 1in the thickness direction z. Each of the first regions 141 a and thesecond region 141 b defines an inwardly curved surface of the substrate1 in plan view. The middle electrodes 23 are disposed on the secondregions 141 b to electrically connect the obverse-surface electrodes 21and the reverse-surface electrodes 22. The middle electrodes 23 includea first middle electrode 231 and a second middle electrode 232 spacedapart from each other in the first direction x.

As shown in FIGS. 22 to 24 and 27, the obverse-surface electrodes 21 areconductive members disposed on the obverse surface 11. In the presentembodiment, the obverse-surface electrodes 21 include a firstobverse-surface electrode 211 on which the semiconductor element 31 ismounted, and a second obverse-surface electrode 212 that is spaced apartfrom the first obverse-surface electrode 211 in the first direction x.As shown in FIGS. 28 and 29, each obverse-surface electrode 21 includesa Cu layer 201 and a plating layer 202 as its components. The Cu layer201 contains Cu and is in contact with the substrate 1. In the presentembodiment, the Cu layer 201 is composed of a first layer 201 a and asecond layer 201 b. The first layer 201 a is in contact with the obversesurface 11, and the second layer 201 b covers the first layer 201 a. Inthe manufacture of the semiconductor device A10, the first layers 201 aare formed by applying copper foil to the obverse surface 11 and also tothe reverse surface 12 of the substrate 1. The second layer 201 b isformed by electroless plating. The second layer 201 b is necessary todispose a middle electrode 23 in the second region 141 b of a concavity14. The plating layer 202 is a metal layer and covers the Cu layer 201(the second layer 201 b in particular). The plating layer 202 may becomposed of a Ni layer, a Pd layer and a Au layer laminated on oneanother. Alternatively, the plating layer 202 may be composed solely ofa Au layer.

As shown in FIGS. 23 and 24, the first obverse-surface electrode 211includes a base segment 211 a, a mounting segment 211 b and a connectingsegment 211 c. The base segment 211 a has an outer perimeter thatincludes apart located on the boundary between the obverse surface 11and one of the inner surfaces 141 (the one on the left in FIG. 24). Thebase segment 211 a has an arc shape with a predetermined radial width.The first middle electrode 231 is connected to the part of the outerperimeter of the base segment 211 a located on the boundary between theobverse surface 11 and the second region 141 b of the inner surface 141.The mounting segment 211 b is where the semiconductor element 31 ismounted. The outer perimeter of the mounting segment 211 b is composedof four sides surrounding the semiconductor element 31. The connectingsegment 211 c connects the base segment 211 a to the mounting segment211 b. The connecting segment 211 c has a strip shape extending in thefirst direction x in plan view.

As shown in FIGS. 23 and 24, the second obverse-surface electrode 212includes a base segment 212 a and a terminal segment 212 b. The basesegment 212 a has an outer perimeter that includes a part located on theboundary between the obverse surface 11 and the other of the innersurfaces 141 (the one on the right in FIG. 24). The base segment 212 ahas a shape symmetrical to the base segment 211 a with respect to anaxis along the second direction y. The second middle electrode 232 isconnected to the part of the outer perimeter of the base segment 212 alocated at the boundary between the obverse surface 11 and the secondregion 141 b of the inner surface 141. The terminal segment 212 b iswhere the wire 4 is bonded to provide an electrical connection to thesemiconductor element 31. The terminal segment 212 b has a strip shapeextending in the first direction x in plan view.

As shown in FIG. 24, the outer perimeter of each obverse-surfaceelectrode 21 is located inward in the obverse surface 11 from theboundary between the obverse surface 11 and the side surfaces 13. Inaddition, the outer perimeter of each obverse-surface electrode 21 (thebase segment 211 a of the first obverse-surface electrode 211 and thebase segment 212 a of the second obverse-surface electrode 212) includesa part located on the boundary between the obverse surface 11 and thefirst regions 141 a of an inner surface 141.

As shown in FIGS. 22, 25 and 27, the reverse-surface electrodes 22 areconductive members disposed on the reverse surface 12. Thereverse-surface electrodes 22 include a first reverse-surface electrode221 and a second reverse-surface electrode 222 spaced apart from eachother in the first direction x. Each reverse-surface electrode 22 has anouter perimeter that includes a part located on the boundary between thereverse surface 12 and an inner surface 141. Each reverse-surfaceelectrode 22 is connected to a middle electrode 23 at the part of theouter perimeter located on the boundary between the reverse surface 12and the second region 141 b of the inner surface 141. More specifically,the first reverse-surface electrode 221 is connected to the first middleelectrode 231 at the part of the outer perimeter located on the boundarybetween the reverse surface 12 and one of the second regions 141 b (theone on the left in FIG. 25). In addition, the second reverse-surfaceelectrodes 222 is connected to the second middle electrode 232 at thepart of the outer perimeter located on the boundary between the reversesurface 12 and the other of the second regions 141 b (one on the rightin FIG. 25). As shown in FIG. 28, each reverse-surface electrode 22includes the Cu layer 201 and the plating layer 202, which are thecommon components with the obverse-surface electrodes 21. Hence, thefirst layer 201 a of each Cu layer 201 is in contact with the reversesurface 12.

As shown in FIG. 25, the outer perimeter of each reverse-surfaceelectrode 22 is located inward in the reverse surface 12 from theboundary between the reverse surface 12 and the side surfaces 13. Inaddition, the outer perimeter of each reverse-surface electrode 22includes a part located on the boundary between the reverse surface 12and the first regions 141 a of an inner surface 141.

As shown in FIGS. 22 and 24 to 27, the middle electrodes 23 areconductive members disposed on the second regions 141 b of therespective inner surfaces 141. In the thickness direction z, each middleelectrode 23 is connected at one end to an obverse-surface electrode 21and at the other end to a reverse-surface electrode 22. Hence, themiddle electrode 23 electrically connects the obverse-surface electrode21 and the reverse-surface electrode 22. In addition, as shown in FIG.28, each middle electrode 23 includes the second layer 201 b of the Culayer 201 and the plating layer 202, which are the common componentswith the obverse-surface electrodes 21 and the reverse-surfaceelectrodes 22. Note that the second layer 201 b is in contact with thesecond region 141 b.

As shown in FIGS. 24 to 26, each middle electrode 23 has an outerperimeter located inward in the inner surface 141 from the boundarybetween the inner surface 141 and the side surfaces 13 as viewed in thethickness direction z. In the present embodiment, each middle electrode23 is disposed on the second region 141 b of an inner surface 141 andnot on the first regions 141 a of the inner surface 141.

As shown in FIGS. 22 to 24, the wiring layers 29 are conductive membersdisposed on the obverse surface 11 and connected to the respectiveobverse-surface electrodes 21. The wiring layers 29 are differentconductive members from the obverse-surface electrodes 21. In thepresent embodiment, one wiring layer 29 is connected to the connectingsegment 211 c of the first obverse-surface electrode 211 and another tothe terminal segment 212 b of the second obverse-surface electrode 212such that each wiring layer 29 is connected to the opposite edges of theconnecting segment 211 c or the terminal segment 212 b in the seconddirection y. In plan view, each wiring layer 29 has a strip shapeextending in the second direction and reaches the opposite edges of theobverse surface 11 that are spaced apart in the second direction y. Eachwiring layer 29 has a narrower width (the length in the first directionx) than the width of the terminal segment 212 b (the length in thesecond direction y). Each wiring layers 29 is composed of the Cu layer201 (the first layer 201 a and the second layer 201 b) and the platinglayer 202, which are the common components with the obverse-surfaceelectrodes 21 and the reverse-surface electrodes 22. The wiring layers29 are disposed to enable electroplating for forming the plating layer202, which is a component of the obverse-surface electrodes 21, thereverse-surface electrodes 22 and the middle electrodes 23.

The semiconductor element 31 plays a central role in the function of thesemiconductor device A10. As shown in FIG. 29, the semiconductor element31 according to the present embodiment is a light-emitting element thatincludes a stack of a p-type semiconductor layer 31 c and a n-typesemiconductor layer 31 d. To be more specific, the semiconductor element31 of the present embodiment is a light-emitting diode, which mayalternatively be a Vertical Cavity Surface Emitting LASER (VCSEL). Thesemiconductor element 31 includes an active layer 31 e between thep-type semiconductor layer 31 c and the n-type semiconductor layer 31 d.The semiconductor element 31 emits light from the active layer 31 e. Thecolor of light emitted by the semiconductor element 31 may be blue. Inthat case, gallium nitride (GaN) is used a main component of the p-typesemiconductor layer 31 c and the n-type semiconductor layer 31 d, andindium nitride (InGaN) as a component of the active layer 31 e. Notethat the semiconductor element 31 may be a light-receiving element, suchas a photodiode or may even be a non-optical element, such as a diode.

As shown in FIG. 29, the semiconductor element 31 has an element obversesurface 31 a facing in the same direction as the obverse surface 11, andan element reverse surface 31 b facing away from the element obversesurface 31 a. The element obverse surface 31 a is apart of the n-typesemiconductor layer 31 d. The element obverse surface 31 a has a secondelectrode 312 formed thereon and connected to the conductive wire 4.That is, the second electrode 312 serves as the N electrode (cathode) ofthe semiconductor element 31. In addition, the element reverse surface31 b is a surface of a first electrode 311 disposed in contact with thep-type semiconductor layer 31 c. Hence, the first electrode 311 servesas the P electrode (anode) of the semiconductor element 31. Thesemiconductor element 31 is mounted on the mounting segment 211 b of thefirst obverse-surface electrode 211 via a conductive bonding layer 32.In this state, the element reverse surface 31 b faces toward the firstobverse-surface electrode 211. Thus, the first electrode 311 iselectrically connected to the first obverse-surface electrode 211 viathe bonding layer 32. The bonding layer 32 according to the presentembodiment may be made of a synthetic resin composed mainly of an epoxyresin containing Ag (so-called Ag paste). The bonding layer 32 is formedby curing a die-bonding material applied to the semiconductor element31.

As shown in FIGS. 23, 24 and 27, the wire 4 is an electricallyconductive component electrically connecting the semiconductor element31 to the second obverse-surface electrode 212. The wire 4 is connectedat one end to the second electrode 312 of the semiconductor element 31,and at the other end to the terminal segment 212 b of the secondobverse-surface electrode 212. The wire 4 may be made of Au, forexample.

As shown in FIGS. 22, 23, 26 and 27, each coating 51 is an electricallyinsulating member disposed on the obverse surface 11 so as to overlapwith at least a part of a concavity 14. The coatings 51 may be made of asolder resist film, for example. In the present embodiment, one coating51 overlaps with an entirety of a concavity 14 and covers the basesegment 211 a of the first obverse-surface electrode 211, and anotheroverlaps with an entirety of a concavity 14 and covers the base segment212 a of the second obverse-surface electrode 212.

As shown in FIGS. 26 and 27, the sealing resin 52 is supported on theobverse surface 11 and covers the semiconductor element 31. As shown inFIGS. 22, 23 and 27, the sealing resin 52 has a pair of outer edges 521spaced apart from each other in the first direction x. Each outer edge521 has a part in contact with a coating 51 and overlapping with aconcavity 14. In the case where the semiconductor element 31 is alight-emitting element (such as a light emitting diode) or alight-receiving element (such as photodiode), a light-transmittingsynthetic resin, such as a silicone resin, is used as the sealing resin52. In particular, in a case where the semiconductor element 31 is alight emitting diode, the sealing resin 52 may contain a phosphor (notillustrated). For example, for the semiconductor element 31 that emitsblue light, the sealing resin 52 containing a yellow phosphor may beused to achieve the semiconductor device A10 that emits white light.Similarly, for the semiconductor element 31 that emits near-ultravioletradiation, the sealing resin 52 containing red, blue and green phosphorsmay be used to achieve the semiconductor device A10 that emits whitelight with high color rendering property. In a case where thesemiconductor element 31 is non-optical element (such as diode), thesealing resin 52 may be a black epoxy resin, for example.

Next, with reference to FIGS. 30 to 39, the following describes anexample of a method for manufacturing the semiconductor device A10.

FIGS. 30 to 39 show a base member 81 (details of which will be describedlater) having a thickness direction z, a first direction x and a seconddirection y, which respectively correspond to the thickness direction z,the first direction x and the second direction y shown in FIGS. 22 to29. In addition, FIGS. 31 and 32 show the sections taken along the sameplane and having the same coverage.

First, as shown in FIGS. 30 and 31, the base member 81 has an obversesurface 811 and a reverse surface 812 facing away from each other in thethickness direction z, and a plurality of holes 813 are formed throughthe base member 81 in the thickness direction z. In FIG. 30, the regionof the base member 81 enclosed by phantom lines (double-dashed lines)corresponds to the substrate 1 of the semiconductor device A10. The basemember 81 may be made of a glass epoxy resin, for example. The holes 813may be formed by drilling or using laser. As shown in FIG. 31, each hole813 has an inner circumferential surface 813 a connected to both theobverse surface 811 and the reverse surface 812. According to thepresent embodiment, a Cu foil layer 821, which is electricallyconductive, is formed on the obverse surface 811 and the reverse surface812. The Cu foil layer 821 corresponds to the first layer 201 a of theCu layer 201. The Cu foil layer 821 may be formed by pressing Cu foilagainst the obverse surface 811 and the reverse surface 812. The Cu foillayer 821 may be omitted.

Next, a conductive layer 82 is formed on the base member 81. Theconductive layer 82 corresponds to the obverse-surface electrodes 21,the reverse-surface electrodes 22 and middle electrodes 23 of thesemiconductor device A10. The process of forming the conductive layer 82includes a step of forming a foundation layer 822, a step of removingparts of the foundation layer 832, and a step of forming a plating layer823.

First, as shown in FIG. 32, a conductive foundation layer 822 is formedon the obverse surface 811, the reverse surface 812 and the innercircumferential surfaces 813 a of the holes 813. The foundation layer822 corresponds to the second layer 201 b of the Cu layer 201 of thesemiconductor device A10. The foundation layer 822 is formed bydepositing Cu by electroless plating. The thus formed foundation layer822 covers the inner circumferential surfaces 813 a of the holes 813. Inaddition, the foundation layer 822 covers the Cu foil layer 821 on theobverse surface 811 and the reverse surface 812. In a case where the Cufoil layer 821 is omitted, the foundation layer 822 covers the obversesurface 811 and the reverse surface 812, in the same manner as it coversthe inner circumferential surfaces 813 a of the holes 813.

Then, parts of the foundation layer 822 are removed. The step ofremoving parts of the foundation layer 822 includes a step of patterningthe foundation layer 822 and a step of forming pairs of auxiliary holes814 through the base member 81.

First, the foundation layer 822 is patterned as shown in FIG. 33. Thepatterning is performed by wet etching, for example. In this case, amixture solution of sulfuric acid (H₂SO₄) and hydrogen peroxide (H₂O₂)is used as an etchant. The patterning of the foundation layer 822involves patterning of the Cu foil layer 821 and the foundation layer822 formed on the obverse surface 811 and the reverse surface 812. Thefoundation layer 822 formed on the inner circumferential surfaces 813 aof the respective holes 813 remains unaffected by the patterning. Bypatterning the Cu foil layer 821 and the foundation layer 822 on theobverse surface 811 and the reverse surface 812, a pair of notches 822 ais formed for each hole 813. More specifically, the notches 822 a ineach pair are formed at opposite sides of a hole 813 in the seconddirection y and spaced apart from the hole 813 in the second directiony.

Next, as shown in FIGS. 34 and 35, a plurality of pairs of auxiliaryholes 814 are formed through the base member 81 such that the auxiliaryholes 814 are continuous with the respective holes 813. The auxiliaryholes 814 in a pair are located at the opposite sides of the hole 813along a line L (the long and short dashed line shown in FIG. 34) passingthrough the center of the hole 813 in plan view. Each auxiliary hole 814thus formed has the center lies the line L and the diameter smaller thanthe diameter of the hole 813. After the auxiliary holes 814 are formed,the notches 822 a are no longer distinct.

Through the steps shown in FIGS. 33 to 35, the removal of portions ofthe foundation layer 822 completes. In this state, as shown in FIG. 34,the outer perimeters of the Cu foil layers 821 and the foundation layers822 remaining on the obverse surface 811 and the reverse surface 812 arespaced apart from the line L. As shown in FIG. 35, in addition, nofoundation layer 822 remains on the inner circumferential surface 814 aof each auxiliary hole 814, which is contiguous with the innercircumferential surface 813 a of a corresponding hole 813. The outerperimeters of the foundation layers 822 remaining on the innercircumferential surface 813 a of the holes 813 are also spaced apartfrom the line L in plan view.

Next, as shown in FIGS. 36 and 37, a plating layer 823 is formed to coatthe foundation layers 822. The plating layer 823 corresponds to theplating layer 202 of the semiconductor device A10. The plating layer 823may be composed of a metal layer formed by electroplating. The metallayer may be a laminate of a Ni layer, a Pd layer and a Au layer.Alternatively, the meal layer may be a Ag layer. The electroplating isperformed using wiring layers 82 a, which extend in the second directiony, as the conductive paths. The wiring layers 82 a correspond to thewiring layers 29 of the semiconductor device A10. Each wiring layer 82 aconnects a Cu foil layer 821 and a foundation layer 822 to another Cufoil layer 821 and another foundation layer 822 that are spaced apart inthe second direction y on the obverse surface 811. The wiring layers 82a are formed together with the conductive layers 82 formed by patterningon the obverse surface 811.

Through the steps shown in FIGS. 32 to 37, the conductive layers 82 arecompleted. The conductive layers 82 remaining on the obverse surface 811correspond to the obverse-surface electrodes 21 and the wiring layers 29of the semiconductor device A10. The conductive layers 82 remaining onthe reverse surface 812 correspond to the reverse-surface electrodes 22of the semiconductor device A10. The conductive layers 82 remaining onthe inner circumferential surfaces 813 a of the holes 813 correspond tothe middle electrodes 23 of the semiconductor device A10.

Next, as shown in FIG. 38, coatings 851 are formed on the obversesurface 811 to overlap with the holes 813 and the pairs of auxiliaryholes 814 in plan view. The coatings 851 correspond to the coatings 51of the semiconductor device A10. After the coatings 851 are formed,semiconductor elements 83 are mounted by die bonding on the conductivelayers 82 on the obverse surface 811. Each semiconductor element 83corresponds to the semiconductor element 31 of the semiconductor deviceA10. After the semiconductor elements 83 are mounted, wires 84 aredisposed by wire bonding to connect each semiconductor element 83 to aconductive layer 82 that is spaced apart on the obverse surface 811 inthe first direction x from the conductive layer 82 on which thesemiconductor element 83 is formed. Each wire 84 corresponds to the wire4 of the semiconductor device A10.

Next, as shown in FIG. 39, a sealing resin 852 is formed to cover thesemiconductor elements 83. The sealing resin 852 corresponds to thesealing resin 52 of the semiconductor device A10. The sealing resin 852may be formed by transfer molding, for example. After the sealing resin852 is formed, the base member 81 and the sealing resin 852 are cut(diced) into individual pieces along the cutting lines CL (the long andshort dashed lines shown in FIG. 39). The cutting lines CL aredetermined by defining grids with lines in the first direction x andlines in the second direction y. Hence, cutting along the cut lines CLin the first direction cuts the wiring layers 82 a together with thebase member 81 and the sealing resin 52. However, cutting along thelines CL in the second direction y cuts the base member 81 alone. Thisis because the lines CL in the second direction y are defined to passthrough the centers of the holes 813 and the pairs of auxiliary holes814. In this manner, this step of cutting along the cutting lines CLdoes not cut the conductive layers 82 at all. Each piece separated inthis step corresponds to a semiconductor device A10. In addition, eachhole 813 and the associated pair of auxiliary holes 814, each of whichextends through the base member 81, together correspond to a concavity14 of the semiconductor devices A10. Though the steps described above,the semiconductor devices A10 are manufactured.

The following describes advantages of the semiconductor devices A10.

The substrate 1 of the semiconductor device A10 has the concavities 14.Each concavity 14 is recessed from a corresponding side surface 13 andhas an inner surface 141 extending from the obverse surface 11 to thereverse surface 12. Each middle electrode 23 is disposed on an innersurface 141 to electrically connect an obverse-surface electrode 21formed on the obverse surface 11 to a reverse-surface electrode 22formed on the reverse surface 12. In this configuration, eachobverse-surface electrode 21 has the outer perimeter located inward inthe obverse surface 11 from the boundary between the obverse surface 11and the side surfaces 13. Similarly, each reverse-surface electrode 22has an edge located inward in the reverse surface 12 from the boundarybetween the reverse-surface electrode 22 and the side surfaces 13. Thisconfiguration ensures that the step of cutting the base member 81 shownin FIG. 39 is performed without forming metal burrs along the edges ofthe obverse-surface electrodes 21 and the reverse-surface electrodes 22of the individual semiconductor devices A10. That is, this configurationmakes it possible to provide a semiconductor devices A10 of a smallersize without metal burrs on the electrodes (obverse-surface electrodes21 and reverse-surface electrodes 22), which impairs the appearanceand/or mountability.

Each middle electrode 23 has the outer perimeter located inward in theinner surface 141 from the boundary between the inner surface 141 andthe side surface 13. In the present embodiment, the middle electrodes 23are located only in the second regions 141 b of the inner surfaces 141.The middle electrodes 23 are important parts for forming solder filletswhen the semiconductor device A10 is mounted on a target printedsubstrate. This configuration enables the step of cutting the basemember 81 shown in FIG. 39 to be performed without forming metal burrsalong the edges of the middle electrodes 23, as with the obverse-surfaceelectrodes 21 and the reverse-surface electrodes 22. This serves tofurther improve the appearance and mountability of the semiconductordevice A10.

In the semiconductor device A10, each obverse-surface electrode 21 hasan outer perimeter including a part located on the boundary between theobverse surface 11 and the first region 141 a of the inner surface 141.Similarly, the reverse-surface electrode 22 has an outer perimeterincluding a part located on a part of the boundary between thereverse-surface electrode 22 and the first region 141 a of the innersurface 141. This configuration ensures that the step of patterning thefoundation layer 822 shown in FIG. 33 is performed to form theconductive layers 82 surrounding the entire peripheral edges of theholes 813. This ensures that the foundation layers 822 formed on theinner circumferential surfaces 813 a of the holes 813 are duly leftunremoved. Thus, the semiconductor device A10 is manufactured withoutdamaging the conductive layers 82 formed on the inner circumferentialsurfaces 813 a (and later formed into the middle electrodes 23 of thesemiconductor device A10).

In the semiconductor device A10, the inner surface 141 of each concavity14 includes the first region 141 a and the second region 141 b both ofwhich define a curved surface. This configuration facilitates theformation of the holes 813 and the auxiliary holes 814 by drilling orusing laser in the step shown in FIGS. 30 and 34.

In the manufacture of the semiconductor device A10, the foundationlayers 822 on the inner circumferential surfaces 813 a of the holes 813may be formed by electroless plating. This ensures that the conductivelayers 82 (which will be formed into the middle electrodes 23 of thesemiconductor device A10) to be appropriately formed on the innercircumferential surfaces 813 a.

The semiconductor device A10 includes the coatings 51 disposed on theobverse surface 11 such that each coating 51 overlaps with at least apart of a concavity 14 in plan view. This configuration prevents thematerial of the sealing resin 52 from flowing into the holes 813 and theauxiliary holes 814 when it is applied in the step of forming thesealing resin 52 shown in FIG. 39. Therefore, the coatings 51 preventthe sealing resin 52 from adhering to the middle electrodes 23 of thesemiconductor device A10. As shown in FIGS. 22, 23 and 27, the sealingresin 52 has the outer edges 521 each having a part in contact with acoating 51 and overlapping with a concavity 14. This means that thesealing resin 52 is kept from adhering to the middle electrodes 23. Inthis manner, the presence of the coatings 51 ensure that the middleelectrodes 23 are exposed to the outside of the semiconductor deviceA10.

FIG. 40 is a sectional view showing the semiconductor device A10 mountedon a wired substrate 61 by ref lowing. FIG. 40 is taken along the sameplane as FIG. 27. The semiconductor device A10 is mounted on the wiredsubstrate 61 with conductive bonding layers 62 between thereverse-surface electrodes 22 and the wired substrate 61. The conductivebonding layers 62 are made of solder cream, for example. The conductivebonding layers 62 are in contact with the middle electrodes 23 inaddition to the reverse-surface electrodes 22. Each conductive bondinglayer 62 has a fillet at a part contacting a middle electrode 23. Thefillet has an inclined surface in the first direction x. The middleelectrodes 23 serve to promote the formation of fillets, which increasesthe bonding strength of the semiconductor device A10 onto the wiredsubstrate 61.

Third Embodiment

The following describes a semiconductor device A20 according to a thirdembodiment of the present disclosure, with reference to FIGS. 41 to 45.In the figures, the same reference signs are used to denote componentsthat are the same as or similar to the components of the semiconductordevice A10 described above. In addition, no description of suchcomponents is repeated. For convenience of illustration, FIG. 41 showsthe semiconductor device A20 is shown in phantom by the imaginary linesindicating the outline of the sealing resin 52.

The semiconductor device A20 differs from the semiconductor device A20in the structures of the obverse-surface electrodes 21 and thesemiconductor element 31. The semiconductor device A20 is similar to thesemiconductor device A10 in that it is an LED package containing alight-emitting diode as the semiconductor element 31.

As shown in FIGS. 41 and 42, the obverse-surface electrodes 21 of thepresent embodiment include a first obverse-surface electrode 213 and asecond obverse-surface electrode 214 spaced apart from each other in thefirst direction x. The semiconductor element 31 is mounted partly on thefirst obverse-surface electrode 213 and partly on the secondobverse-surface electrode 214. As with the obverse-surface electrodes 21of the semiconductor device A10, the obverse-surface electrodes 21 ofthis embodiment are composed of a Cu layer 201 (including a first layer201 a and a second layer 201 b) and a plating layer 202.

As shown in FIGS. 41 and 42, the first obverse-surface electrode 213 hasa base segment 213 a, a mounting segment 213 b and a connecting segment213 c. The base segment 213 a has an outer perimeter including a partlocated on a part of the boundary between the obverse surface 11 and oneof the inner surfaces 141 (one on the left in FIG. 42). In plan view,the base segment 213 a has an arc shape with a predetermined radialwidth. A first middle electrode 231 is connected to the outer perimeterof the base segment 213 a at a part located on the boundary between theobverse surface 11 and the second region 141 b of the inner surface 141.The mounting segment 213 b is where the semiconductor element 31 ismounted. The mounting segment 213 b has a strip shape extending in thesecond direction y in plan view. The connecting segment 213 c connectsthe base segment 213 a to the mounting segment 213 b. The connectingsegment 213 c has a shape of a strip extending in the first direction xin plan view.

As shown in FIGS. 41 and 42, the second obverse-surface electrode 214has a base segment 214 a, a mounting segment 214 b and a connectingsegment 214 c. The second obverse-surface electrode 214 has a shapesymmetrical to the shape of the first obverse-surface electrode 213 withrespect to an axis along the second direction y. The base segment 214 acorresponds to the base segment 213 a of the first obverse-surfaceelectrode 213. A second middle electrode 232 is connected to the edge ofthe base segment 214 a at a part located on the boundary between theobverse surface 11 and the second region 141 b of the inner surface 141.The mounting segment 214 b corresponds to the mounting segment 213 b ofthe first obverse-surface electrode 213. The mounting segment 214 b iswhere the semiconductor element 31 is mounted. The connecting segment214 c corresponds to the connecting segment 213 c of the firstobverse-surface electrode 213. The connecting segment 214 c connects thebase segment 214 a to the mounting segment 214 b. In the presentembodiment, as shown in FIGS. 41 to 45, the semiconductor element 31 hasa first electrode 311 and a second electrode 312 on the element reversesurface 31 b that faces toward the obverse surface 11. The firstelectrode 311 is electrically connected to a p-type semiconductor layer(now illustrated) of the semiconductor element 31. The second electrode312 is electrically connected to an n-type semiconductor layer (notillustrated) of the semiconductor element 31. That is, the semiconductorelement 31 of the present embodiment is so-called a flip-chip element.The first electrode 311 is electrically connected to the firstobverse-surface electrode 213 via a conductive bonding layer 32. Thesecond electrode 312 is electrically connected to the secondobverse-surface electrode 214 via another conductive bonding layer 32.The bonding layers 32 of the present embodiment is formed from solderpaste, for example. More specifically, the bonding layers 32 are made ofthe solder paste cured by reflowing. The present embodiment allows thewire 4 to be omitted.

The following describes advantages of the semiconductor device A20.

As with the semiconductor device A10, the semiconductor device A20includes the obverse-surface electrodes 21, the reverse-surfaceelectrodes 22 and the middle electrodes 23. Each obverse-surfaceelectrode 21 has an outer perimeter located inward in the obversesurface 11 from the boundary between the obverse surface 11 and the sidesurface 13. In addition, each reverse-surface electrode 22 has an outerperimeter located inward in the reverse surface 12 from the boundarybetween the reverse-surface electrode 22 and the side surface 13. Thisconfiguration also makes it possible to provide a semiconductor devicesA20 of a smaller size without metal burrs on the electrodes(obverse-surface electrodes 21 and reverse-surface electrodes 22), whichimpairs the appearance and/or mountability.

Since the semiconductor element 31 is so-called a flip-chip element, thesemiconductor device A20 includes no wires 4, requiring no space forsuch wires 4. Thus, a larger semiconductor element 31 may be used toimprove the brightness as compared with the semiconductor device A10 ofa comparable package size. Reversely, a semiconductor element 31 of asize comparable to that included in the semiconductor device A10 may beused to allow the semiconductor device A20 to be smaller.

The present disclosure is not limited to the specific embodimentsdescribed above. Various design modifications may be made to thespecific configurations of each part of the present disclosure.

Specifically, the second and third embodiments described above encompassthe following clauses.

Clause B1.

A semiconductor device comprising:

a substrate having:

-   -   an obverse surface and a reverse surface facing away from each        other in a thickness direction;    -   a side surface connected to both the obverse surface and the        reverse surface; and    -   a concavity recessed from the side surface, the concavity having        an inner surface extending from the obverse surface to the        reverse surface;

at least one obverse-surface electrode disposed on the obverse surface;

a reverse-surface electrode disposed on the obverse surface;

a middle electrode disposed on the inner surface to electrically connectthe obverse-surface electrode and the reverse-surface electrode; and

a semiconductor element mounted on the obverse-surface electrode,

wherein the obverse-surface electrode has an outer perimeter locatedinward in the obverse surface from a boundary between the obversesurface and the side surface, and

wherein the reverse-surface electrode has an outer perimeter locatedinward in the reverse surface from a boundary between the reversesurface and the side surface.

Clause B2.

The semiconductor device according to Clause B1,

wherein the middle electrode has an outer perimeter located inward inthe inner surface from a boundary between the inner surface and the sidesurface as viewed in the thickness direction.

Clause B3.

The semiconductor device according to Clause B2,

wherein the inner surface has a first region recessed from the sidesurface and a second region recessed from the first region, and

wherein the middle electrode is disposed on the second region.

Clause B4.

The semiconductor device according to Clause B3,

wherein each of the first region and the second region is a curvedsurface.

Clause B5.

The semiconductor device according to Clause B3 or B4,

wherein the outer perimeter of the obverse-surface electrode has a partlocated on a boundary between the obverse surface and the first region,and

wherein the outer perimeter of the reverse-surface electrode has a partlocated on a boundary between the reverse surface and the first region.

Clause B6.

The semiconductor device according to any of Clauses B1 to B5,

wherein the side surface has a pair of regions spaced apart from eachother in one direction perpendicular to the thickness direction, and

wherein the concavity is recessed from both the regions.

Clause B7.

The semiconductor device according to Clause B6,

wherein the at least one obverse-surface electrode comprises a pluralityof obverse-surface electrodes including:

-   -   a first obverse-surface electrode on which the semiconductor        element is mounted; and    -   a second obverse-surface electrode spaced apart from the first        obverse-surface electrode in the one direction, and

wherein the semiconductor device further comprises a wire thatelectrically connects the semiconductor element to the secondobverse-surface electrode.

Clause B8.

The semiconductor device according to Clause B7,

wherein the semiconductor element has an element obverse surface facingin the same direction as the obverse surface and an element reversesurface facing away from the element obverse surface,

wherein the element reverse surface is a part of a first electrode thatis electrically connected to the first obverse-surface electrode via aconductive bonding layer, and

wherein a second electrode is formed on the element obverse surface andthe wire is connected to the second electrode.

Clause B9.

The semiconductor device according to Clause B6,

wherein the at least one obverse-surface electrode comprises a pluralityof obverse-surface electrodes including a first obverse-surfaceelectrode and a second obverse-surface electrode spaced apart from eachother in the one direction, and

wherein the semiconductor element is mounted on both the firstobverse-surface electrode and the second obverse-surface electrode.

Clause B10.

The semiconductor device according to Clause B9,

wherein the semiconductor element has an element reverse surface facingtoward the obverse surface, and

wherein the semiconductor device further comprises a first electrode anda second electrode that are formed on the element reverse surface, thefirst electrode being electrically connected to the firstobverse-surface electrode via a conductive bonding layer, the secondelectrode being electrically connected to the second obverse-surfaceelectrode via a conductive bonding layer.

Clause B11.

The semiconductor device according to any of Clauses B1 to B10,

wherein each of the obverse-surface electrode, the reverse-surfaceelectrode and the middle electrode includes a Cu layer that is incontact with the substrate.

Clause B12.

The semiconductor device according to any of Clauses B1 to B11,

wherein the semiconductor element comprises a light emitting diode, and

wherein the semiconductor device further comprises a sealing resincovering the semiconductor element.

Clause B13.

The semiconductor device according to Clause B12,

wherein the sealing resin contains a phosphor.

Clause B14.

The semiconductor device according to Clause B12 or B13, furthercomprising

a coating disposed on the obverse surface and overlaps with at least apart of the concavity as viewed in the thickness direction of thesubstrate.

Clause B15.

A method for manufacturing a semiconductor device, comprising:

forming a hole extending through a base member in a thickness direction,the base member having an obverse surface and a reverse surface facingaway from each other in the thickness direction;

forming an electrically conductive foundation layer on the obversesurface, the reverse surface and an inner circumferential surface of thehole; and

removing a part of the foundation layer,

wherein the removing of a part of the foundation layer includes removingparts of the foundation layer such that parts of the foundation layerleft unremoved on the obverse surface and the reverse surface have outeredges spaced apart from a line passing through a center of the hole asviewed in a thickness direction of the base member.

Clause B16.

The method according to Clause B15,

wherein the removing of a part of the foundation layer includes forminga pair of auxiliary holes through the base member, the pair of auxiliaryholes being continuous with the hole and located at opposite sides ofthe hole along the line passing through the center of the hole as viewedin the thickness direction of the base member.

Clause B17.

The method according to Clause B15 or B16,

wherein the forming of a foundation layer includes forming thefoundation layer on the inner circumferential surface of the hole byelectroless plating.

The invention claimed is:
 1. A semiconductor device comprising: asubstrate including an obverse surface, a reverse surface and a sidesurface that connects the obverse surface and the reverse surface toeach other, the substrate being formed with a recess that recedes fromthe side surface in plan view, the recess having an inner side faceextending from the obverse surface to the reverse surface; an obverseelectrode disposed on the obverse surface; a reverse electrode disposedon the reverse surface; an intermediate electrode disposed on the innerside face of the recess and electrically connecting the obverseelectrode and the reverse electrode to each other; and a semiconductorelement disposed on the obverse electrode, wherein the obverse electrodeincludes a peripheral edge that is offset inwards of the obverse surfacewith respect to a boundary between the obverse surface and the sidesurface, and the reverse electrode includes a peripheral edge that isoffset inwards of the reverse surface with respect to a boundary betweenthe reverse surface and the side surface.
 2. The semiconductor deviceaccording to claim 1, wherein the intermediate electrode has aperipheral edge that is offset inwards of the recess with respect to aboundary between the inner side face of the recess and the side surfaceof the substrate.
 3. The semiconductor device according to claim 1,wherein the inner side face of the recess includes a first region and asecond region, the first region receding from the side surface of thesubstrate, the second region receding from the first region, and theintermediate electrode is disposed on the second region.
 4. Thesemiconductor device according to claim 3, wherein the first region isexposed from the intermediate electrode.
 5. The semiconductor deviceaccording to claim 3, wherein each of the first region and the secondregion forms a curved surface.
 6. The semiconductor device according toclaim 5, wherein the second region is greater in curvature radius thanthe first region in plan view.
 7. The semiconductor device according toclaim 3, wherein a part of the peripheral edge of the obverse electrodeoverlaps with a part of a boundary between the obverse surface and thefirst region in plan view, and a part of the peripheral edge of thereverse electrode overlaps with a part of a boundary between the reversesurface and the first region in plan view.
 8. The semiconductor deviceaccording to claim 1, wherein the side surface of the substrate includesa pair of regions spaced apart from each other in plan view, and therecess recedes from each of the pair of regions.
 9. The semiconductordevice according to claim 1, further comprising a wire, wherein theobverse electrode comprises a first obverse electrode and a secondobverse electrode spaced apart from the first obverse electrode, thesemiconductor element being disposed on the first obverse electrode, andthe wire electrically connects the semiconductor element and the secondobverse electrode.
 10. The semiconductor device according to claim 9,further comprising an electroconductive bonding layer, wherein thesemiconductor element has an element obverse surface and an elementreverse surface opposite to the element obverse surface, wherein theelement reverse surface is electrically connected to the first obverseelectrode via the bonding layer, and the element obverse surface isformed with an electrode to which the wire is bonded.
 11. Thesemiconductor device according to claim 1, wherein each of the obverseelectrode, the reverse electrode and the intermediate electrodecomprises a Cu layer held in contact with the substrate.
 12. Thesemiconductor device according to claim 1, further comprising alight-transmitting sealing resin, wherein the semiconductor element is alight-emitting diode, and the sealing resin covers the light-emittingdiode.
 13. The semiconductor device according to claim 12, wherein thesealing resin contains a fluorescent material.
 14. The semiconductordevice according to claim 1, further comprising a coating memberdisposed on the obverse surface of the substrate, wherein the coatingmember overlaps with at least a part of the recess in plan view.
 15. Thesemiconductor device according to claim 14, wherein the coating memberhas an elongated rectangular shape in plan view and has an end face thatis flush with the side surface of the substrate.
 16. The semiconductordevice according to claim 14, wherein the semiconductor element isexposed from the coating member.
 17. The semiconductor device accordingto claim 14, wherein the coating member is smaller in thickness than thesubstrate.
 18. The semiconductor device according to claim 14, furthercomprising a sealing resin covering the semiconductor element, wherein apart of the sealing resin is in contact with an obverse surface of thecoating member.
 19. The semiconductor device according to claim 18,wherein the sealing resin is made of one of a silicone resin or an epoxyresin, and the coating member is made of a solder resist.
 20. Thesemiconductor device according to claim 18, wherein the sealing resinhas a straight outer edge spaced apart from the side surface of thesubstrate and offset toward the semiconductor element in plan view.